A．It is difficult to define.
B．Its causes are often unknown.
C．Psychologists disagree about how to treat it.
D．Its symptoms often go unnoticed.

A．To explain the effect it has on mental illness.
B．To suggest that it is easier to diagnose than mental illness.
C．To discuss the role of medicine in clinical psychology.
D．To show the similarities between physical and mental illness.

A．Another means of measuring normal behavior.
B．Why some politicians aren't well adjusted.
C．How an individual' s behavior is influenced by therapy.
D．Problems often encountered by psychologists.